The present invention is in the environment of handling utility poles, specifically apparatus for pulling and setting poles which are supporting electric power lines and the like. Many of these poles are thirty and forty feet in length and are sunk in the ground to a depth of six to eight feet minimum. Obviously a network of power lines and utility poles is present in all types of terrain and environments including heavily populated residential and commercial developments along with more sparsely populated rural areas. In the past, utility poles have been handled by means of large boom trucks with which utility companies move a load of poles to a centralized location and the boom is then used to lift the poles off the truck, after which the poles are manually transported to the site of installation. At repair or installation time, a new hole must be dug and the new pole set therein, prior to lifting the old utility pole out of the ground and carrying it back to the boom truck. This process alone can take several men a period of hours to perform, and does not include the task of transferring the wiring and other mechanical components from the old utility pole to the new pole. This procedure is generally done by a lineman physically climbing the old pole to release the wiring, and then a second man climbing the new pole to attach the wiring thereto.
As commerical and residential developments became more heavily populated, and in some areas of the country extremely dense, it became more and more difficult for the utility companies to make necessary repairs to existing utility poles or to install new networks of utility wires. The boom trucks which are conventionally used for handling the utility poles are large and because of the height of the operating boom the trucks require a substantial clearance in order to manipulate the poles. Further, because of the necessary clearance for the boom and because of the increasingly densely developed areas, it became necessary that the boom trucks be parked increasingly farther away from the actual installation site. Therefore, because of the time and expense involved with handling the utility poles, many times repairs were postponed until absolutely necessary, to the detriment of the utility system. The cost of manually handling the poles also substantially increases the cost of developing and installing new utility systems because as many as six to eight men might be tied up for hours to replace only one or two poles.
When some of the small scale earth and material moving equipment such as the skid steer loaders became available, attachments were available for these small loaders which could be used for digging holes for setting utility poles. However, there was no equipment available which could be used to transport the poles to or from the actual work site, and which could also lift the old pole out of the ground and then insert the new pole. It was originally believed that the small scale of these loaders would be detrimental or prohibitively dangerous in handling these extended length utility poles because of the weight and length of the pole. Originally the balance of the loader was believed to be compromised by the size of the utility poles. It was to overcoming these restrictions that the inventor turned in development of an attachment that could be used for transporting, lifting or pulling, and setting utility poles without compromising the balance and function of the loader.
The present invention is such a device and has been successfully tested in the environment of handling conventional wooden utility poles or the newer aluminum poles which are used for supporting streetlights and the like. The device is an attachment for the small loaders such as the Toyota, the Clark Bobcat.TM., and other like machinery; which attachment can be utilized to support a utility pole that is placed thereon by a boom truck, and after reaching the installation site move the pole into position for setting in the ground. The same attachment is also utilized for grasping and pulling an old utility pole from the ground, pivoting it up and in position over the loader for transporting back to the primary supply truck where the pole is removed from the loader by a boom and placed on the truck.
The present invention is an hydraulically operated gripping and supporting mechanism that is attached to the loader. In use the gripper is centered around the utility pole, after which the hydraulic control is activated to close the gripping arm to engage the pole and hold it securely through the movement of pulling or setting. The gripping and supporting mechanism also secures the pole for transporting in a position wherein the pole is parallel to the longitudinal axis of the loader. The mechanism holds the pole without slippage during a pivotal movement from that position wherein the pole is parallel to the longitudinal axis of the loader, to a position wherein the pole is perpendicular to the longitudinal axis of the loader and thereby in a position for pulling or setting.
The improved handling mechanism additionally includes a plurality of removable stud devices on the gripping surfaces for improving the gripping action on aluminum or other types of materials which might have a slippery surface. The studs are also useful when handling wooden utility poles during wet or damp conditions.
The handling mechanism attachment itself is a self-contained attachment which is attached to the loader lift arm by a simple leverage action lock, taking only two to three minutes to remove one attachment (such as an auger used for digging the hole for the pole) and replace with the pole handling attachment. In addition to the aforementioned gripper, the mechanism includes a cradle in which the pole is supported during pivotal movement. Further, an auxillary, permanently mounted pole stabilizer means is attached to the upper surface of the loader to receive and stabilize the end portion of the utility pole during its transport position.
It is therefore a primary objective of the present invention to provide an apparatus for handling utility poles by attachment of the apparatus to small scale loaders and earth moving equipment. Another primary objective of the present invention was to provide such a handling mechanism on small scale equipment which could be utilized in densely populated and developed areas. Other objectives include the provision of an apparatus which could be attached to the selected loader and utilize hydraulic and steerage controls existing on the loader; the provision of a utility handling apparatus which could be quickly attached or detached from the loader by the operator, while remaining in the loader; and the provision of such a handling apparatus having a minimum number of components, thereby maximizing efficiency and dependability. Other objectives and advantages of the apparatus will become apparent to those skilled in the art as they study the following detailed description in conjunction with the accompanying drawings. In the drawings: